The EMG Plugin API can be used to implement custom functionality in EMG with very little overhead. An EMG plugin can be called when a message is received and before and after it is sent by implementing different functions in the plugin.

The steps to build a plugin are:

• Download plugin-3.0.tar.gz
• Extract it:
  gzip -d plugin-3.0.tar.gz
  tar xvf plugin-3.0.tar
• Change directory and build it:
  cd plugin-3.0
  ./build.sh myplugin

The sample "myplugin.c" includes a skeleton for a plugin. In order for the plugin to do something code needs to be added to "myplugin.c".

To get EMG to use the plugin you need to install and configure it.

• Create /etc/emg/plugins
  mkdir /etc/emg/plugins
• Copy the plugin
  cp myplugin.so.0.0 /etc/emg/plugins
  chmod 755 /etc/emg/plugins/myplugin.so.0.0
• Add a PLUGIN section to server.cfg
  PLUGIN myplugin <
  INSTANCES=1
  LIBRARY=/etc/emg/plugins/myplugin.so.0.0
  >
• Define that the plugin should be used on a connector
  CONNECTOR xyz <
  ...
  PLUGIN=myplugin
  ...
  >
• Restart emgd

More information

EMG Plugin API - Manual